Detection, quantification, and magnetic field dependence of solid-state O-17 NMR of X-O-Y (X,Y = Si,Ti) linkages: Implications for characterizing amorphous titania-silica-based materials

O-17 solid-state NMR spectra from hybrid TiO2-SiO2-based materials can clearly distinguish Si-O-Si, Si-O-Ti, and Ti-O-Ti linkages. Spectra are reported from these groups for applied magnetic fields from 5.6 to 14.1 T, which allows their NMR parameters to be deduced. The quantitative accuracy of these spectra is investigated and the implications for detecting nanoscale phase separation discussed. Changes in the local structure with functionalization of the silicon alkoxide (R'Si-lambda(OR)(4-x)) and modification of the titanium precursor by acetylacetone are examined